Fourdrinier drainage foil assembly



June 2, 1970 E N ET AL 3,515,636

' FOURDRINIER-JDRAINAGE FOIL ASSEMBLY Filed 001;. 2. 1967 it: Q3. Lomgnkm 2,, M 44% J /UpRMA/u United States Patent O 3,515,636 FOURDRINIERDRAINAGE FOIL ASSEMBLY George E. Reynolds and Lee R. Loughran, Appleton,

Wis., assignors to Allis-Chalmers Manufacturing Company, Milwaukee, Wis.

Filed Oct. 2, 1967, Ser. No. 672,117 Int. Cl. D21f 1/38 U.S. Cl. 162-3523 Claims ABSTRACT OF THE DISCLOSURE A portion of a paper making machineis disclosed where paper stock discharged from a headbox is depositedupon a Fourdrinier type web forming wire provided with drainage foilassemblies beneath the wire (substituted for table rolls), and a foilassembly is supported beneath the wire by a support mechanism carried onrails beneath and parallel to the edges of the wire. The assemblyincludes a body which is connected to the support mechanism and a foilcap mounted on top of the foil body. The foil body and foil cap are ofspecial design providing a spring loaded dovetail connection between thefoil body and foil cap.

CROSS-REFERENCE TO RELATED PATENT APPLICATION A mechanism, for adjustingthe angle of a foil relative to the bottom surface of a Fourdrinierwire, is disclosed in this application and which is the subject of ourcopending U.S. patent application entitled Angularly Adjustable SupportMechanism for Fourdrinier Drainage Foil, Ser. No. 672,118, filed Oct.10, 1967 BACKGROUND OF THE INVENTION Field of the invention Thisinvention relates to paper making machines having drainage foils,deflectors, forming boards or the like, beneath a Fourdrinier type webforming wire and in particular to a foil assembly including a bodycarrying a removable and replaceable foil cap beneath the Fourdrinierwire.

Description of the prior art A concept involved in this invention isthat of providing blades, now commonly called drainage foils, beneath aFourdrinier wire in the position formerly occupied by table rolls, toachieve superior drainage of water through the bottom of the wire. Theevolution of this concept to present day forms is illustrated by thefollowing patents: British Pat. 399,739 in 1933; British Pat. 717,798 in1954; U.S. Pat. 2,744,454 in 1956; U.S. Pats. 3,017,930 and 3,027,941 in1962; U.S. Pat. 3,140,225 in 1964; and U.S. Pats. 3,165,440 and3,201,308 in 1965. In all of these prior art arrangements some provisionis made for replacing a foil after it has become worn but with aconsiderable variation in the speed and convenience of such replacement.

SUMMARY OF THE INVENTION It is a primary object of the present inventionto provide a new and improved drainage foil assembly for promoting waterremoval through the bottom of a Fourdrinier web forming wire.

Another object of the present invention is to provide a drainage foilassembly or the like with a new and im- 3,515,635 Patented June 2, 1970proved arrangement for quickly replacing a removable cap.

Another object of the present invention is to provide a new and improvedarrangement for mounting a removable foil cap on a body supported belowthe bottom surface of a Fourdrinier wire.

According to a preferred embodiment of the present invention, aFourdrinier wire drainage foil assembly includes a body portionsupported in a generally horizontal position below a Fourdrinier wire,with a foil cap mounted on top of the foil body. The foil cap isattached to the body by a dovetail tongue and groove type joint. Thedovetail tongue is defined by the bottom surface of the foil cap andprojects downwardly. The top surface of the foil body defines a portionof the dovetail groove including a generally horizontal groove bottomsurface and one groove wall angularly inclined upwardly from the bottomsurface in a direction to be partly over the bottom surface. A flexiblestrip spring is connected to the body adjacent the groove surface on theopposite side thereof from the one groove wall defined by the foil body.The strip spring is arranged to project upwardly from the groove bottomsurface and is inclined toward the one groove Wall defined by the body.The strip spring therefore provides a second groove wall and therebycompletes the formation of a dovetail groove complementary with thetongue of the coil cap. The strip spring is biased toward the groovewall defined by the body and therefore firmly holds the dovetail tongueof the foil cap but allows easy withdrawal and insertion of the tonguethrough an open end of the slot.

Other features and objects of the invention that have been attained willappear from the more detailed description of an embodiment of theinvention shown in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a diagrammatic side elevationview of a portion of a paper making machine showing a portion of aheadbox, a breast roll, Fourdrinier wire and drainage foil assembliesaccording to the present invention;

FIG. 2 is an enlarged and fragmentary view of one of the drainage foilassemblies of FIG. 1, showing the assembly in greater detail and partlyin section taken along line IIII of FIG. 1; and

FIG. 3 is a view partly in section taken along line III,III in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing andFIG. 1 in particular, a portion of a paper making machine is shownwherein a headbox 1 discharges pulp through a slice opening 2 to depositthe pulp on a Fourdrinier wire 3 as it leaves a breast roll 4 that isturning in the direction indicated by the arrow. A plurality of drainagefoil assemblies 5 are shown arranged beneath the wire 3 and mounted onside rails 6.

Referring to FIG. 2, the foil support assembly 5 is shown as having alower support member 10, an upper support member 11 that may be raisedand lowered by a threaded post 12 carried on top of support member 10and secured to rail 6 by a bolt 13, a foil body 14, and a foil angleadjusting mechanism 15 connecting foil body 14 to upper support member11. A replaceable foil cap 16 is mounted on top of the foil body in amanner that will appear as the description of the disclosed apparatusproceeds.

The foil angle adjusting mechanism 15 includes a pair of vertical plates30, 31. Plate 30 is adjacent foil 14 and is attached thereto. Plate 31is adjacent upper support member 11 and is attached to that member. Thetwo plates 30, 31 have vertical surfaces that engage in a vertical planeAA and cooperate to define therebetween a mated key 32 and keyway 33. Asshown in FIG. 2, in the preferred embodiment the key 32 projects fromplate 30 into a keyway 33 in plate 31. The key 32 may however projectfrom plate 31 into a keyway 33 in plate 30. As shown in FIG. 3 theconfiguration of the key and keyway 32, 33 is arcuate with a radius Remanating from a point on an axis coincident with the leading knife-edge34 of foil cap 16. The term leading as herein used to describeknife-edge 34 refers to the orientation shown in FIG. 1 where it isshown that the knife-edge 34 is the lead edge with respect to theapproach of wire 3 toward foil cap 16.

The foil angle adjusting mechanism 15 also includes a variable lengthlink assembly 40 pivotally connected on one end to the vertical plate 31by any suitable means, such as for example a shaft 46 mounted to rotaterelative to plate 31. The other end of assembly 40* includes a bolt 50that projects through a slot 51 in plate 31 to plate 30 where an endportion 52 of bolt 50 is threadingly attached to plate 30. The slot 51in plate 31 is oriented (see FIG. 3) to present its major axis C--Cgenerally perpendicular to a radius R from a point on leading edge 34.

The foil cap 16 is attached to the foil body 14 by a dovetail tongue andgroove type joint that will now be described. As shown in FIG. 2 adovetail tongue 17 is formed on the bottom of foil cap 16 and has agenerally horizontal surface 18, a first tongue wall 19 spaced back ofthe leading knife-edge 19, to define therebetween the downwardlyprojecting dovetail tongue 17. A third wall 21 defined by cap 16 isspaced back to the second wall 20 and cooperates therewith to define aslot 22. The tongue walls 19, 20 are inclined downwardly in divergingrelation to each other to form with the surface 18 the dovetail tongueconfiguration 17. A portion of a dovetail groove 23 is defined on top ofsaid foil body 14 by a generally horizontal surface 24 and a groove wall25. A flexible strip spring 26 is attached to the foil body 14 by capscrews 27. The strip spring 26 projects upwardly from groove surface 24in converging relation to wall 25 and into slot 22. Wall 25, surface 24and strip spring 26 complete the formation of a dovetail groove 23 infoil body 14 which is complementary to dovetail tongue 17 and the spring26 is biased toward wall 25 to firmly hold tongue 17 and foil cap 16 inposition relative to foil body 14 and Fourdrinier wire 3.

In the operation of the described apparatus the position of the foilassembly along rail 6 may be adjusted by loosening bolts 13 and thensliding lower support member along rail 6 until assembly 5 is at adesired location. If it is desired to adjust the vertical position offoil 14 relative to wire 3, the bolt 13 is first loosened. Post 12 maythen be turned to project downwardly a greater distance below uppersupport 11 which has the effect of raising support 11 and attachedstructures, relative to lower support 10 and wire 3. Turning post 12 toproject downwardly a lesser distance below support 11 of course willlower support 11 and all structures carried thereby. When post 12 hasbeen turned to carry foil 14 at the desired level relative to wire 3and/or assembly 5 is moved to a desired location on rail 6, then bolt 13is tightened to secure the apparatusin position.

The angular tilt of foil 14 relative to wire 3 may be adjustedindependently of any adjustments such as have been described and may ormay not have been performed. To adjust the angular tilt of foil 14 bolts50 and 53 are first loosened. Then the adjustable length link assembly40 is adjusted to change the effective length of the link assembly 40.If, from the position shown in FIG. 3, assembly 40 is adjusted toincrease the effective length of assembly 40, the end portion 52 of boltwill move plate 30 and attached foil 14 relative to plate 31 andattached support 11. Key 32 and keyway 33 will guide this movement to bepivotal clockwise (as seen in FIG. 3) and about the axis coincident withthe leading knifeedge 34 of foil cap 16. Shortening link assembly 40will pivot plate 30 and attached foil 14 counterclockwise (as seen inFIG. 3). The pivotal movement in either clock direction will however beabout the axis coincident with leading knife-edge 34 of foil cap 16 andthe position of edge 34 relative to Fourdrinier wire 3 will not change.Thus the described pivotal adjustment of foil 14 cannot inadvertentlybring knife-edge 34 in a position that may expose the foil 14 toexcessive wear or cause the edge 34 to cut the Fourdrinier wire 3.

In time the top surface of the foil cap 16 and its leading knife-edge 34will become worn and require replacement. To remove the cap 16 it ismerely withdrawn endwise, i.e., to the left or right as shown in FIG. 2.A replacement cap is then mounted on the body 14 by inserting tongue 17into the dovetail groove 23 and sliding the cap 16 along the top of thebody until it is centered thereon.

From the foregoing detailed description of the present invention it hasbeen shown how the objects of the invention have been attained in apreferred manner. However, modifications and equivalents of thedisclosed concepts such as readily occur to those skilled in the art areintended to be included within the scope of this invention. Thus, thescope of this invention is intended to be limited only by the scope ofthe claims such as are or may hereafter be appended hereto.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. Fourdrinier wire drainage foil assembly and the like including a pairof elements one of which is a foil body adapted for support in agenerally horizontal position and the other of which is a cap mounted ontop of said body and connected thereto, said body having a top surfaceand said cap having a bottom surface cooperating to define therebetweena dovetail tongue and a portion of a dovetail groove, said portion ofsaid dovetail groove including a generally horizontal groove surface anda first transverse groove wall, and a flexible strip spring connectedadjacent said groove surface on the opposite side thereof from saidfirst groove wall and with said strip spring projecting away from saidgroove surface in a direction converging toward said first groove wallto provide a second wall for said groove and thereby define a dovetailgroove com-plernentarily engaging said dovetail tongue, and said stripspring being biased toward said first groove wall to removably engageand firmly hold said dovetail tongue therebetween.

2. A drainage foil assembly according to claim 1 in which said dovetailtongue projects downwardly from the bottom surface of said foil cap,said portion of said dovetail groove is defined in the topof said foilbody, and said flexible strip spring is connected to said body tocomplete the formation of a dovetail groove in said body complementaryto said dovetail tongue projecting from said foil cap.

3. A drainage foil assembly according to claim 2 in which said foil caphas a leading knife-edge and said tongue projecting from said foil capis spaced away from a vertical plane through said leading knife-edge;said tongue is defined by a generally horizontal surface, a firsttransverse tongue wall spaced in close proximity from said verticalplane, and a second transverse tongue wall remote from said verticalplane; a third transverse wall defined by said foil cap is spaced fromsaid second wall in a direction away from said tongue; and said second3,515,636 I 5 6 tongue wall and said third wall cooperate to define aslot REUBEN FRIEDMAN, Primary Examiner into which said strip springprojects to provide complete complementary engagement of the dovetailgroove with T. A. GRANGER, Assistant Examiner the dovetail tongue.

U.S. Cl. X.R.

6 References Cited UNITED STATES PATENTS 3,446,702 5/1969 Buchanan162352 X

